I'm making a water-themed dungeon for my current cungeon-crawling adventure, and it occurred to me just how little information I could find regarding the effects of waterfalls.

The rough water bit I understand, but do waterfalls deal nonlethal damage to people wading underneathe them?

Do they create turbulant water below them as well?

Do they create mist, granting concealment in nearby squares? If so, how much concealment, and over what sort of distance?

What is the Spot DC to see through a waterfall?

What other effects might these grand occurances have on a game?

wizarddog

02-11-2010, 10:26 AM

Would depend on the size of the waterfall(s).
A little one pouring into a lagoon is not going to be an issue. Niagara falls on the other hand, is an issue.
http://en.wikipedia.org/wiki/Niagara_Falls
But that was just for going over the falls. Depending on what the terrain near the fall is like will also depend on how lethal it is.

As far as doing damage, going under a fall would be more like suffering non-lethal damage for a tough D&D PC.

As much as waterfalls are concerned, I think you need only indicate them as difficult terrain and as potential areas for concealment and cover.

tesral

02-12-2010, 01:05 AM

Examples Angel falls is the highest in the world, but standing at the bottom will only get you wet. By the time the water falls that far it is a mist.

All of the mentioned effects are possible, how much water is falling how far? It is all a matter of degree.

I would say any degree of water in the curtain will obscure vision to some degree if not totally.

Waterfalls tend to be deeper right at the point of the falling watter. The turbulence digs out the bottom more. Exceptions do exist, like very small falls or something like Angel Falls. or very hard rock.

Non lethal damage only if the water is pounding amounts falling a good distance.

Dark Cloaked Figure

02-12-2010, 03:30 AM

Alright, thanks. But... erm...

Any chance for some sort of guide to help me with the creation of waterfalls? Say water will be falling... 30 feet. Will that produce mist? How much? What would the Spot DC for something behind it be?

d-_-b

02-12-2010, 05:09 AM

A guide is a bit hard to come by, but here's what I think you should do:

1) familiarize yourself with the the effects of darkness, rain, water, fog, smoke, etc. and they way the impose penalties to spot and listen checks as well as granting concealment. Here's a quick link: http://www.systemreferencedocuments.org/resources/systems/pennpaper/dnd35/soveliorsage/wildernessAndEnvironment.html

2) forget about the real world requirements to achieve the desired effect -your players aren't going to care if the water fell 500 ft. or 500 yards. They are going to care about their vision being obscured by mist from the falling water as well as the deafening roar of it.

3) a watery dungeon should impose difficulties to accelerated movement, so check up on movement skills: Balance, Climb, Jump, and Tumble.

Other than this you might want to play around with your water faucet -perhaps in combination with a spoon- to experience first hand what conditions produce which effect, e.g. a raging torrent or a glass like sheet of water.

tesral

02-12-2010, 09:54 AM

Alright, thanks. But... erm...

Any chance for some sort of guide to help me with the creation of waterfalls? Say water will be falling... 30 feet. Will that produce mist? How much? What would the Spot DC for something behind it be?

Again, how much? Puddle Jumper creek or the Mississippi? Size matters. A 30 foot fall can be a picturesque romantic scene where you can easily bathe under it, or a torrent that could wash you away.

At 30 feet the water will not be moving very quickly. Speed of the current plus the law of 32/32. 32 feet per second per second. So it takes slightly less than a second for the water to fall.

The most important factors are going to be aeration and volume.

If the stream above is smooth and slow the water will be fairly clear. If it is quick and tumbling over rocks the water will have air churned into it and will be foamy and opaque. in the best of circumstances it will be hard to make out anything through it.

The degree of comfort will be a volume issue. If I pour a gallon of water on you every second from the roof, you will be wet and perhaps annoyed. If I dump 100 gallons of second on you it will knock you down. Water is heavy, to the tune of 8.8 pounds per gallon. The water in the average 29 gallon fish tank weighs 255 pounds. 100 gallons of water weighs 880 pounds. However if I spread that 100 gallons over a 25 foot width it becomes more like 4 gallons a second hitting you. Something you can deal with.

So you can see a simple sent of game rules is not in the offing. There are simply too many variables to deal with. It boils down to "What do you want it to do?" If you want the water opaque and damaging describe it as a thunderingly heavy flow of churned water. If you want mist, have the water hit rocks that scatter it, or come off a rapids that do the same above.

Dark Cloaked Figure

02-12-2010, 02:35 PM

Ah, thank you, Tesral. I think that just about answers everything I was looking to know, save one thing.

If there is to be concealing mists, can I get a vague ballpark for how much area these mists would cover?

cigamnogard

02-12-2010, 05:00 PM

Also one thing I noticed had not been mentioned (or maybe I missed it) was - depending on the size of the waterfall - a modifier for listen check.

tesral

02-12-2010, 11:49 PM

Ah, thank you, Tesral. I think that just about answers everything I was looking to know, save one thing.

If there is to be concealing mists, can I get a vague ballpark for how much area these mists would cover?

OK, my one really close encounter with Niagara, which is a really BIG waterfall, the mists filled the whole gorge, but the concealing part was only very close to the falls themselves. There was a enough water that you get a rain coat and needed it, but you can easily see from one side of the gorge to the other or down the gorge.

Also one thing I noticed had not been mentioned (or maybe I missed it) was - depending on the size of the waterfall - a modifier for listen check.

Again, water can do funny things. You would think that Niariga would be defening. It's not. It's a hissing noise that is quieter than you would think it should be, almost a background white noise. Like every shower in the city running at once. It's easy enough to talk over,, but I can see where it deadens sound at a distecne. The riverside was the quietest tourist trap I have ever been to.

Dark Cloaked Figure

02-13-2010, 04:45 AM

Thank you, tesral.

tesral

02-13-2010, 10:13 AM

A caveat to the falling water speed. The falling speed of a propelled object vs. a still one was proved by the Mythbusters to be equal. So no matter what the speed of the current is, the water will not fall faster than 32 feet per second per second. Water is the laziest substance on Earth. It never does more than it absolutely must to find it lowest level. The word with water is volume. The more the more dangrous.

Waist Deep In The Big Muddy

It was back in nineteen forty-two,
I was a member of a good platoon.
We were on maneuvers in-a Loozianna,
One night by the light of the moon.
The captain told us to ford a river,
That's how it all begun.
We were -- knee deep in the Big Muddy,
But the big fool said to push on.

The Sergeant said, "Sir, are you sure,
This is the best way back to the base?"
"Sergeant, go on! I forded this river
'Bout a mile above this place.
It'll be a little soggy but just keep slogging.
We'll soon be on dry ground."
We were -- waist deep in the Big Muddy
And the big fool said to push on.

The Sergeant said, "Sir, with all this equipment
No man will be able to swim."
"Sergeant, don't be a Nervous Nellie,"
The Captain said to him.
"All we need is a little determination;
Men, follow me, I'll lead on."
We were -- neck deep in the Big Muddy
And the big fool said to push on.

All at once, the moon clouded over,
We heard a gurgling cry.
A few seconds later, the captain's helmet
Was all that floated by.
The Sergeant said, "Turn around men!
I'm in charge from now on."
And we just made it out of the Big Muddy
With the captain dead and gone.

We stripped and dived and found his body
Stuck in the old quicksand.
I guess he didn't know that the water was deeper
Than the place he'd once before been.
Another stream had joined the Big Muddy
'Bout a half mile from where we'd gone.
We were lucky to escape from the Big Muddy
When the big fool said to push on.

Well, I'm not going to point any moral;
I'll leave that for yourself
Maybe you're still walking, you're still talking
You'd like to keep your health.
But every time I read the papers
That old feeling comes on;
We're -- waist deep in the Big Muddy
And the big fool says to push on.

Waist deep in the Big Muddy
And the big fool says to push on.
Waist deep in the Big Muddy
And the big fool says to push on.
Waist deep! Neck deep! Soon even a
Tall man'll be over his head, we're
Waist deep in the Big Muddy!
And the big fool says to push on!

Another factor to take into account is the variance in temperature. One could conceivably see the formation of fog due to the introduction of cooler running water impacting more stationary water at the base. Even the simple difference in elevation could cause varying effects. Let alone the sun heating up rocks at the base and what not.

TheYeti1775

03-04-2010, 11:46 AM

Real life effects.
Where I grew up in the mountains there was a series of 3 falls, the first one was just water running over hard rock for about a 50ft drop into a pool with 2 other streams joining there.
You couldn't climb it without rope (we tried as kids), but it would push you off either.

The second one off the pool with the joining streams went over an overhang 25-30ft, creating a nice little cave area that remained dry. We camped there a lot.
The water running down would beat you up if you went through it directly. As it was it was slick coming in through the sides, a bit misty.